VOGONS


First post, by .legaCy

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I know i know what is new about it? PCChips boards failing?
With that being said, i have two boards, one is socket 7 and one is socket 370(the m748).
Both of the boards seems to be dead, no beep, no post code on my PCI analyzer card(just zero), CPU warming up.
Both have AT connectors and ATX connectors, i have tested with known good processors and ram and power supply.
i have checked the cmos jumper, and both have one jumper near the keyboard and power connector.
Any hints?

Reply 1 of 10, by cyclone3d

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Could be bad caps.. or maybe even just a dead CMOS battery.

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Reply 2 of 10, by .legaCy

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cyclone3d wrote:

Could be bad caps.. or maybe even just a dead CMOS battery.

About the caps it is plausible, the socket 370 has visible bad capacitors, i will do a capacitor map for both and i will buy new caps for them.
About the bad battery, seems interesting the socket 7 one is missing the battery and the socket 370 have one, i will try a brand new battery before.
I also will do verify both bios chips.

Reply 3 of 10, by TheMobRules

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I have experienced the same with a couple of Slot 1 PCChips boards, one is my old M747 and the other is an M715 I found in a discarded case. Replacing capacitors and reflashing the BIOS with an external programmer didn't help.

It seems that this sudden death syndrome is quite common on PCChips boards... no beeps, no signs of life, chips get warm but not too hot, caps are OK and the board responds to the ATX on/off. POST cards don't show anything either, it's like they lost their will to live 🤣

Maybe something related to the VRMs/MOSFETs? I don't know...

Reply 5 of 10, by dionb

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If you have visibly bad caps, do something about that before considering baking or other more exotic things. Most boards of that age that spontaneously die have bad caps and most others have a corrupt BIOS. Reflashing the EEPROM (or using a new one) is a good second step after checking the caps.

Reply 6 of 10, by .legaCy

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dionb wrote:

If you have visibly bad caps, do something about that before considering baking or other more exotic things. Most boards of that age that spontaneously die have bad caps and most others have a corrupt BIOS. Reflashing the EEPROM (or using a new one) is a good second step after checking the caps.

Yes there are visible bad caps on the Socket 370 board, the socket 7 has no visible bad caps but it don't mean that they are good.
the caps on the Socket 370 are G-Luxon branded, on the socket 7 they are TEAPO branded.
maybe a suitable nichicon replacement will bring those boards back to life.
When i find some time to spare i will do both boards capacitor maps and find some Nichicon replacements.

I took some pictures
https://imgur.com/a/rYRt8ga

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Reply 7 of 10, by ATauenis

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What Clock and Reset indicators are displaying on your PC Analyser? Values of them may help in repair process.

2×Soviet ZX-Speccy, 1×MacIIsi, 1×086, 1×286, 2×386DX, 1×386SX, 2×486, 1×P54C, 7×P55C, 6×Slot1, 4×S370, 1×SlotA, 2×S462, ∞×Modern.

Reply 8 of 10, by .legaCy

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ATauenis wrote:

What Clock and Reset indicators are displaying on your PC Analyser? Values of them may help in repair process.

Socket 7 board:
2 digit display: 00
RST: OFF
FRAME: ON
IRDY: OFF
CLK:ON
CPU getting warm.

Socket 370 board:
2 digit display: 00
RST:ON
FRAME:ON
IRDY:OFF
CLK:ON

BIOS dumps:
Socket 7 https://www.dropbox.com/sh/efz8izkve26r7qp/AA … jSlva8ipXa?dl=0
Socket 370 https://www.dropbox.com/s/6eh37ng54kysz1d/bios.BIN?dl=0

The thing that i think it is weird is all boards that i recapped even with bad caps they showed signs of activity on the analyzer card.

Reply 9 of 10, by ATauenis

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.legaCy wrote:

The thing that i think it is weird is all boards that i recapped even with bad caps they showed signs of activity on the analyzer card.

The boards are barely alive. If the reset LED lights up when reset button is pushed, then clock and reset circuits are in good condition. Check temperature of chips on boards. If none of them is very hot, I have bad news: chipset might be dead. Otherwise, the hottest chip might be the causer of this topic.

---

Oops, only S7 board seems to be repairable. S370 mobo has stuck Reset, thus the board is dead at all.

Last edited by ATauenis on 2018-05-22, 20:39. Edited 1 time in total.

2×Soviet ZX-Speccy, 1×MacIIsi, 1×086, 1×286, 2×386DX, 1×386SX, 2×486, 1×P54C, 7×P55C, 6×Slot1, 4×S370, 1×SlotA, 2×S462, ∞×Modern.

Reply 10 of 10, by .legaCy

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ATauenis wrote:
.legaCy wrote:

The thing that i think it is weird is all boards that i recapped even with bad caps they showed signs of activity on the analyzer card.

The boards are barely alive. If the reset LED lights up when reset button is pushed, then clock and reset circuits are in good condition. Check temperature of chips on boards. If none of them is very hot, I have bad news: chipset might be dead. Otherwise, the hottest chip might be the causer of this topic.

Well this socket 370 board i bought it as working for the equivalent of US$5 with the cpu, ram, and all the brackets and one network card, but the seller shipped it on a carton box with the board wrapped in bubble wrap.
Since its RST is on even without reset signal i think one scenario of ESD is quite probable, i got a full refund on the board and now i'm trying to make it work.
The socket 7 i found at the office inside an asus motherboard box, never worked thou.