HP-82183A... Problem with ASTEC 0950-0408 :(

[Titi]

Hello,

I get a HP-82183A but it don't work. When I turn on the printer, the led BATT flashing and led POWER is dark.

Connect to my 41c :



PRINT ERROR.

If I turn off the printer, the message is PRINTER OFF. If I remove paper, I obtain "OUT OF PAPER". Ok... But, if I press PAPER ADVANCE button, there is nothing.

Sometimes, these elements are hot...



So, I try to test Astec... It's no good


(Some strange spots)



ASTEC 0950-0408

Code:

  o      o      o      o
 0,5v    '      -      -
  
  
  
  
               OFF / ON
  
  o                    o
 14v                   - 
 
              ( )       (*)

14v, ok but only another contact is working (a very little 0,5V). Elsewhere, 0v

So, I would like to change this element. Do you know if I can find Astec 0950-0408 in USA perhaps ?

I think motherboard is nice.


(click to enlarge)


(click to enlarge)

Thank you very for your help and best regards from France !

Thierry Loiseau

[Dave Frederickson]

The ASTEC part is the print head power supply, PS1. I think you need to troubleshoot the primary power supply problem, first. There's a nice troubleshooting procedure in the service manual, available on the MoHPC flash drive.

Dave

[mfleming]

Hello Thierry!

On an older 82143A board I have, this part appears as a separate printed circuit board with discrete parts soldered to it, then the board itself is soldered to the main printer board. What you seem to have is a later enclosed version of that same board. You won't be able to find a replacement, as this was undoubtedly made specifically for HP.

The printer service manual identifies the part as PS1 (Power Supply), part number 0950-0408. In the schematic, pins 1, 3 & 6 are Ground, pin 2 is a control signal driven by the Intensity switch, pin 4 is battery input and pin 5 is the output. That may help you in checking if the part works.

The printer diagnostics suggest checking the motor and drive parts if the printer doesn't respond to the Paper Advance button. With the power off, try turning the large wheel at the end of the shaft where the motor belt connects, in order to advance the printer head a short distance. When the power is turned on, the printer should try to return the head to the rest position. If the motor does activate, then you likely have a mechanical problem.

The printer service manual can be found on the MoHPC DVD and provides much more detail. In repairing one of these, I found the problems to be mostly mechanical, such as proper position and alignment of the speed sensor and position limit switch.

Good luck!
~Mark

[Dave Frederickson]

Per the Improper Turn-On Troubleshooting Procedure, Table 4-3, be sure that the battery is good before starting.

[Titi]

Thank you very much for your reply... So, here my head-printer... I compare with the HP Museum's picture :




Strange ? My S/N is 2336S30032 (1983 ?)

[rprosperi]

(06-26-2017 06:31 PM)Titi Wrote:  Strange ? My S/N is 2336S30032 (1983 ?)

These printers came out in 1980 I believe (mine is '81 and I did not buy it upon introduction) so an '83 unit can easily be considered a late (improved) version.

[Titi]

(06-26-2017 06:02 PM)Dave Frederickson Wrote:  Per the Improper Turn-On Troubleshooting Procedure, Table 4-3, be sure that the battery is good before starting.

Ok. My battery 82033A give 5V. I test with another charger, Eurocharger 82066B.
This HP-82183A was with a 82059D so.

Now, in the motherboard, I get 18v & 5v ! But, LED Power is off ?

[Dave Frederickson]

(06-26-2017 09:25 PM)Titi Wrote:  Ok. My battery 82033A give 5V. I test with another charger, Eurocharger 82066B.
This HP-82183A was with a 82059D so.

Now, in the motherboard, I get 18v & 5v ! But, LED Power is off ?

It looks like you can troubleshoot the printer with either a battery or AC adapter, but the Power LED is the first priority.

Refer to the service manual for Turn-On Troubleshooting Procedures. You can find the service manual either on the MoHPC flash drive or it can be downloaded from the HP41 website.

Mark mentioned mechanical failures. It doesn't hurt to clean the slide switches and lubricate them with a dielectric grease.

Dave

[Paul Berger (Canada)]

(06-26-2017 09:25 PM)Titi Wrote:  

(06-26-2017 06:02 PM)Dave Frederickson Wrote:  Per the Improper Turn-On Troubleshooting Procedure, Table 4-3, be sure that the battery is good before starting.

Ok. My battery 82033A give 5V. I test with another charger, Eurocharger 82066B.
This HP-82183A was with a 82059D so.

Now, in the motherboard, I get 18v & 5v ! But, LED Power is off ?

There is +5V generated in two places on the board, one is the print head voltage is fed into 78L05 regulator, the other is a switching regulator that generates the +5V logic voltage, the 9100-0425 pulse transformer is part of that regulator. The output from the logic 5V supply and the output from the 78L05 are compared and the output from that generates an active low power good signal which enables the buffers in the 74LS365 chip and two of the gates on that chip have their inputs tied low and the outputs tied together which turns on the power LED and also enables a few other things. See Tony Duell's hand drawn schematic at http://www.hpmuseum.net/document.php?hwfile=3014

BTW I have an old style logic, the 0950-0408 module is not encapsulated, that I believe does work, I connected power and the power light does come on and I verified that the print head voltage and +5V logic where both present. I believe it was a working printer that I scavenged mechanical parts from to fix a 82162A and a printer in a 97. You may have it for the cost of shipping, send me an email if you are interested.

Paul.

[Titi]

Thank you Paul. May be I'm interest ?!

My first control from the Service Manual (I make a PDF).





I find 5.7v about U3 (pin 6)... out of range [4.9v... 5.1v].



So, about the 2nd step, there is no CR8 element on my motherboard (and no CR7 too) ?!




Thierry

[Paul Berger (Canada)]

(06-29-2017 05:25 PM)Titi Wrote:  Thank you Paul. May be I'm interest ?!

Send me an email with your address and I can tell you how much it will cost to send it to you.

(06-29-2017 05:25 PM)Titi Wrote:  My first control from the Service Manual (I make a PDF).


So, about the 2nd step, there is no CR8 element on my motherboard (and no CR7 too) ?!

The one I am looking at does not have those components either it does not even have pads for CR7. One thing I would check would be the reference voltage at pin 7 of U3, if it is wrong the output from the +5V logic supply will be wrong. The theory section starting on page 2-4 explains in some detail how this 5V regulator works.

(06-29-2017 05:25 PM)Titi Wrote:  Thierry

Paul.

[Titi]

(06-29-2017 08:18 PM)Paul Berger (Canada) Wrote:  One thing I would check would be the reference voltage at pin 7 of U3, if it is wrong the output from the +5V logic supply will be wrong. The theory section starting on page 2-4 explains in some detail how this 5V regulator works.

I find +5.04v here ! U3-pin 3 : 13.92v (with jumper W1)

[Paul Berger (Canada)]

(06-29-2017 09:35 PM)Titi Wrote:  

(06-29-2017 08:18 PM)Paul Berger (Canada) Wrote:  One thing I would check would be the reference voltage at pin 7 of U3, if it is wrong the output from the +5V logic supply will be wrong. The theory section starting on page 2-4 explains in some detail how this 5V regulator works.

I find +5.04v here ! U3-pin 3 : 13.92v (with jumper W1)

Ok well the +5V logic supply is a little bit on the high side, but even so the power light should come on. Comparator U3D is the control of of the 5V logic regulator, when I measure the inputs to it pin 8 is about 150mV less than pin 9 this would be due to the offset voltage for that comparator, the measurements that you quote suggest that there is an offset voltage of nearly 700mV and that is way too much, but still like I said previously, the power LED should still come on. Pin U3-6 should be higher than U3-7 which should result in pin1 being low, which in turn pulls down pins 1,2,14, and 15 of U9 74LS365, a hex tri-state non-inverting buffer. Pins 1 and 15 enable the outputs and 2 and 14 are inputs to two of the buffers Since this is a non-inverting buffer the outputs 3 and 13 (tied together) should also be low and that should turn on the power LED as well as enable some other parts of the printer.


The voltage on U3-3 is ok. It is connected to the print head voltage which is variable depending on the intensity setting, I believe that with the board out of the printer it would be the equivalent of the lightest setting, I measure about the same voltage with the intensity turned all the was down.

Paul.

Paul.

[Titi]

(06-30-2017 01:06 AM)Paul Berger (Canada) Wrote:  

(06-29-2017 09:35 PM)Titi Wrote:  I find +5.04v here ! U3-pin 3 : 13.92v (with jumper W1)

The voltage on U3-3 is ok. It is connected to the print head voltage which is variable depending on the intensity setting, I believe that with the board out of the printer it would be the equivalent of the lightest setting, I measure about the same voltage with the intensity turned all the was down.

I measure with the board in... I find +17.4v with hightest setting.
My other tests about U3 (pin #)

1 : 5.42
2 : 6.45
3 : 13.89 (Vh)
4 : 5.09
5 : 4.75
6 : 6.42
7 : 5.05
14: 17.26
C7+ : 4.50 (Vbs)
U2 :5.07 (Vp) / 0.68 / 13.91

[Paul Berger (Canada)]

(06-30-2017 05:10 AM)Titi Wrote:  

(06-30-2017 01:06 AM)Paul Berger (Canada) Wrote:  The voltage on U3-3 is ok. It is connected to the print head voltage which is variable depending on the intensity setting, I believe that with the board out of the printer it would be the equivalent of the lightest setting, I measure about the same voltage with the intensity turned all the was down.

I measure with the board in... I find +17.4v with hightest setting.
My other tests about U3 (pin #)

1 : 5.42
2 : 6.45
3 : 13.89 (Vh)
4 : 5.09
5 : 4.75
6 : 6.42
7 : 5.05
14: 17.26
C7+ : 4.50 (Vbs)
U2 :5.07 (Vp) / 0.68 / 13.91

OK so the measurements above would suggest that the - input of U3D (8), which is connected to Vp, is more positive than the + (9) which is connected to reference voltage this should cause the output from U3D to be zero but that does not appear to be the case. Pins 1 and 2 of U3 should also be low according to your measurements. My best guess would be that the U3 is defective. Since the output of U3D is high this should mean that Q2 is turned off and the voltage at the base of Q1 should be less that Vh so that Q1 is at least partially turned on this would also account for the rise in output voltage (Vp) when you change the intensity setting which caused Vh to rise. I find subs quoted for U3 1826-0287 as LM339 or LM2901 both of which are comparators with the same pinout and very similar characteristics for this application I think either one would be suitable.

Paul.

[Titi]

So, about "U2 :5.07 (Vp) / 0.68 / 13.91", my measure is from "-" of battery.
I don't know if this test is correct (sorry, I'm really not an electronics )

If the U3 is dead : "I find subs quoted for U3 1826-0287 as LM339 or LM2901 both of which are comparators with the same pinout and very similar characteristics for this application I think either one would be suitable."

Then, how to confirm the default of U3 to be sure ?

Best regards & thank you Paul for your help !

Thierry

[Paul Berger (Canada)]

(06-30-2017 05:02 PM)Titi Wrote:  So, about "U2 :5.07 (Vp) / 0.68 / 13.91", my measure is from "-" of battery.
I don't know if this test is correct (sorry, I'm really not an electronics )

If the U3 is dead : "I find subs quoted for U3 1826-0287 as LM339 or LM2901 both of which are comparators with the same pinout and very similar characteristics for this application I think either one would be suitable."

Then, how to confirm the default of U3 to be sure ?

Best regards & thank you Paul for your help !

Thierry

Are you still using a setup similar what you had in you first pictures where you where using an external AA battery holder? The center pin of U2 should be ground and at the same potential as the "-" of the battery this might suggest you don't have a real good connection between the "-" of the battery and where you connected inside the printer so it is dropping a little voltage or maybe there is a slight offset in your meter, does it read 0 when you short the meter leads together? Attaching the "-" lead to a ground point inside the printer might bring the voltage on the center pin closer to zero.

Because there is an offset of about 0.68V it means that the other voltage readings are pobably a bit higher than they really are, but that does not change the results, the comparators in U3 work on the difference in voltages on the inputs and since the offset would affect all voltages the difference between them would not change, so I still think that U3 is defective.

For U3 what I am saying is LM339 and LM2901 are nearly identical so either one could be used to replace U3.

Paul.

[wil7]

hi,
on your first post there is a picture with C7 (elco) on the nearby view of your astec supply. the negative bonding of this cap looks very ugly(burned).
check if still fastened(bonded) to the alu cap. does it get hot? when available check
with an osciloscope. there should be no ripple. altenativly check with an multimeter.
on the dc-volt setting you should get your desired voltage, on ac-voltage setting there should be only small ripple voltage(about .5v). from the picture i would guess the cap is ca150mikro-farad 25v. this could serve as stabiliser for the astec-supply? when faulty the hole printer subsystem will get fussy...
wil

[Titi]

Well, about your comments (merci), I tell that :

• I'm order LM339N
  

My last tests is from the original batteries and Eurocharger. The first test is from a make pack 4x1.5AA. I would like really to see a Renaissance of this printer

[Titi]

I received theses...