HP-65 1333A18516 - [SOLVED] request for advice
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06-14-2024, 11:29 PM
(This post was last modified: 06-30-2024 07:24 PM by albertofenini.)
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HP-65 1333A18516 - [SOLVED] request for advice
Hello everyone
we are trying to restore a unit acquired as a non working unit, when arrived it looked in very good conditions, so we thought it was a easy one ... The main problem was that "it didn't turn on" ..... When this happens the first test we do is to move the logic board in a different known to be working unit, and see what happens, this test proved that the logic board was indeed working The unit had been previously restored as we found the gummy wheel replaced, although the coupler between the motor and the worm gear appears to be original Few cables were desoldered and the three led modules had been replaced, will post more details about that soon Anode and Cathode drivers appeared to be original although all of that area had been reworked We began resoldering the card reader and the motor cables, we removed the led modules, the anode and the cathode drivers, cleaned everywhere and resoldered nicely everything back in place However, when turned on it remained with a totally black display With the card reader now connected we tried to read a card, and even if the result was unkonwn because of the non working display, the card went thru smoothless A small step forward ... We tested the inductances that are placed above the leds and those are just fine, we checked the capacitor, the inductance and the resistance that are placed just below the switches and those are fine as well We checked the capacitor in the upper corner, and that it's also fine Eventually we temporarily replaced the original keyboard pcb, which was in very good condition, with a "correded but working" one and the display turned magically on We tried then to read the card again and that also worked fine, so we now know that the card reader is at least reading cards properly We decided then to transplant the led modules, the anode and the cathode drivers from the "corroded but working" keyboard pub to the original one, but nevertheless the display remains off .... We came to the conclusion that it has to be a faulty trace in the keyboard pcb unless someone can point to a possible different cause We also checked all the joint that connect the two faces of the pcb and these are all good with no cold or bad connections Any idea how could we find the broken trace(s) ??? Should we start from the logic board connector or should we investigate more in the led modules area ? Keep in mind that all the components have been proven be in a working condition Thanks for any help !!! Take care Pictures can be found here : HP-65 1333A18516 Edoardo & Alberto |
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Messages In This Thread |
HP-65 1333A18516 - [SOLVED] request for advice - albertofenini - 06-14-2024 11:29 PM
RE: HP-65 1333A18516 - request for advice - teenix - 06-15-2024, 01:00 AM
RE: HP-65 1333A18516 - request for advice - albertofenini - 06-15-2024, 01:33 AM
RE: HP-65 1333A18516 - request for advice - teenix - 06-15-2024, 05:35 AM
RE: HP-65 1333A18516 - request for advice - albertofenini - 06-15-2024, 07:25 PM
RE: HP-65 1333A18516 - request for advice - albertofenini - 06-16-2024, 06:21 PM
RE: HP-65 1333A18516 - request for advice - teenix - 06-17-2024, 02:06 AM
RE: HP-65 1333A18516 - request for advice - albertofenini - 06-17-2024, 05:20 AM
RE: HP-65 1333A18516 - [SOLVED] request for advice - albertofenini - 06-30-2024, 07:11 PM
RE: HP-65 1333A18516 - [SOLVED] request for advice - teenix - 06-30-2024, 11:44 PM
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