GVP 1230 problems

[rkauer]

 Power Supply could be the issue!

 Some of those AT-PSUs don't have a fine 5V line in the tolerance rating (i.e. aprox. 4.95~5.25V). Check the voltage with a multimeter.

 Other clue: 1D3 revisions are buggy, so check the motherboard if you don't have fixed it already.

[rkauer]

 Bad caps is a good start. Replace all electrolytic ones. Easy and inexpensive (if you have SMD soldering skills).

 I've have post a list of all needed caps here on a.org.

 But I'm too lazy to search for the link ;-) .

 So here is the "shopping list":

18 caps (all electrolytics)

3 units 10Uf x 16 volts SMD

5 || 22Uf x 35 Volts SMD

2 || 47Uf x 16 Volts SMD

4 || 100Uf x 65 Volts SMD

2 || 470Uf x 16 Volts Regular size

2 || 1000Uf x 10 Volts Regular size


Be happy!

[rkauer]

 BTW: two of the 22uF 35V caps are intended for use in the audio out circuit.

 It's a bug in the project! Nevertheless they still function as they are, prefer to change those two with unpolarized equivalents (maybe hard to find).

[rkauer]

webmany wrote:
Don't caps bulge when they go bad?

 Not always. Sometimes they simply dry (and lost capacitance in the process).

 Bulging caps are common only in high voltages (>60V).

[rkauer]

webmany wrote:
Did a test of the PSU and on the it went between 4.85 -> 5.20.  Could this be enough to cause my problems?

Also, I am tracking down the capacitors.

 Anything less than 4.92V aren't good enough. But when the power oscillate among those values you surely get a problem with the PSU.

 But there is a chance of you doing the wrong measure approach: you must read the value with the PSU attached to the Amiga.

 +5V must be rock steady around just one voltage! Doesn't care if it be 4.95 or 5.08, only must be steady.

 Replace your PSU ASAP.