Hello all, I have a mth 30-1127-1 railking ps1 Hiawatha. I like this engine a lot but it makes this annoying buzzing sound when it runs. Sounds are garbled and hard to hear. I believe it is the speaker. It does it at almost all voltages. I tried the tether to no avail. I will check it out tomorrow.
Thanx.
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Speaker is high on the list, after that it's possible it's one of the boards.
If the speaker is not the problem, try this: with the engine in neutral and power applied (with the tender shell off), touch the circuit board and the buzzing sound goes away, the circuit has a bad ground. These are very difficult to trace and repair. I have seen this problem in the MTH proto1 boards.
Usually the buzzing at most track voltages above about 7 Volts is failure of the voltage regulator allowing too high a voltage to the top board and over driving the audio amp.
I can't remember the last time I had to change a speaker on a PS-1. They fail so infrequently unless the engine was abused. G
GGG, Is it repairable at all? If it is what you are saying and it is not repairable for a fair cost, this will be a good excuse to upgrade it to ps2 or 3.
Yes, The VR can be replaced. The bottom board is very repairable.
Not the caps. When the caps fail you usually have lower voltage than required for various functions.
G
Doesn't exist. What I know is from reverse engineering/tracing boards and repairing them. After you repair enough, you start seeing the common failures. Most caps are on the bottom board used on the various power supply circuits to create higher voltages than the rectified AC input. In my experience top board hardware failures have been very, very, very low. Like 1 or 2 out of 100. G
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