Socket 7 MB oscillator repair - need information on SC653DYB clock generator chip \ VOGONS

Socket 7 MB oscillator repair - need information on SC653DYB clock generator chip

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First post, by mita

Posted on 2024-02-20, 20:17

mita Offline

Rank Newbie

Rank: Newbie
Posts: 63
Joined: 2024-01-27, 15:33

Hi,

I try to repair an MB, see the closest MB on retroweb: https://theretroweb.com/motherboards/s/pcpart … ib804ds-35-8804

My MB is a bit different on the oscillator circuit and the power section, see the attached picture. The symptom: there is no clock, CLK out - pin 3 I assume - is about 3.4VDC on the scope. I replaced the crystal but the situation is the same. I was not able to find datasheet for this IC therefore I am asking help to locate one. Unfortunately I was not able to find a similar one. Maybe the closest is the ISC9169 but the pinout and the number of pins are different I am sure. Pin 1 of the SC653 is GND, pin1 of ISC9169 is VCC. Interestingly pin2, pin3 is the same, the xtal connections.

Any help, suggestion is appreciated!

Reply 1 of 2, by Thermalwrong

Posted on 2024-02-20, 22:04

Thermalwrong Offline

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Rank: Oldbie
Posts: 1873
Joined: 2018-03-18, 19:24
Location: England

Search for just "imi sc653" minus the quote marks. The last letters of parts like this after the numbers, say they're SRAM, PLL or DRAM etc are usually things like the package type, revision, operating temperature - so searching for the package name open ended like this often results in better hits.

There's a full PDF on the first page of google - uploaded here just in case it goes away.

Reply 2 of 2, by mita

Posted on 2024-02-22, 21:16

mita Offline

Rank Newbie

Rank: Newbie
Posts: 63
Joined: 2024-01-27, 15:33

Thermalwrong wrote on 2024-02-20, 22:04:

Search for just "imi sc653" minus the quote marks. The last letters of parts like this after the numbers, say they're SRAM, PLL or DRAM etc are usually things like the package type, revision, operating temperature - so searching for the package name open ended like this often results in better hits.

There's a full PDF on the first page of google - uploaded here just in case it goes away.

Thank you your help! Document sent to admint to upload .

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