Help No Squalk & No Talk

[stevebm1]

not sure if you have read this?

http://www.flipper-fr.org/pdf/AS-2518-61 Theory of operation.pdf

 

[Arv]

How's the TMS5200 chip?

 

[Johnnyo]

I have seen some of the details about the flashes and what they mean but not this document as such TBH a lot of it goes over my head Steve
I assuming the flashes are correct but reading this the amp side could be faulty the LM3900 I/Cs and the power amp chip.
@Arv The TMS chip was extracted and cleaned.

 

[Ruk]

I had a really long drawn out job trying to fix my S&T board but I was lucky enough to be given a donor board that I could use to swap out some of the chips (thanks to @kevlar ). The last fault I had to sort was some severe clipping of the audio (not as bad as yours though) and I had a feeling that it lay in the filter section (pre amp) and by using the doc posted by @stevebm1 I replaced the components relating to that section and it sorted it... thank bloomin' flip cos it really was a head scratcher and it was so close to doing an impression of a frisbee

Also, I'm not sure if it's worth removing R9 and measuring the resistance as I think this is tied to the timing of the TMS5200... nowt lost. There is also a cap there but this is more likely to be OK.

 

[Johnnyo]

Thanks @Ruk at the moment its manic where I work and I'm not getting home till late not getting enough time to sit and digest all this info. Never had a sound board go bad before so that why I'm fumbling in the dark at the moment.

 

[pinballmania]

Hard to diagnose remotely. Your booting up ok so self tests appear in order. Otherwise the test button wouldn't work. There are some discernible sounds but sounds like the second half only of the boot test sequence sounds. Could be eprom problem or other logic issue. Time to have someone look at it.