Maxtrac 300 D34 Power Problem
Moderator: Queue Moderator
Maxtrac 300 D34 Power Problem
Just got this radio off of fleabay.... Got it out of box to check it out. The power supply I am using already is known working with my base radio hooked up to it. I go to plug in the power to the maxtrac, and it kinda sparks a bit (kinda like when you hook up jumper cables when jumping a car). At the same time, my base radio shuts off, and when I unhook power from maxtrac, my base radio turns back on. In that time, other than the sparks at the power plug, the maxtrac is dead as a rock. Removed 16 pin jumper with same response. Ign sense wire is not present in plug, which doesn't mean much... Was to be in known working condition when removed, so they say... Anyways, any ideas or suggestions are welcomed. I am not a tech, just a farmer, so I guess I want to know if it's worth taking to the shop before my return time is up. Thanks
-
jackhackett
- Posts: 1518
- Joined: Tue Jun 10, 2003 8:52 am
Sounds like the radio is shorted out. Usually the cause of this is somebody hooking the power up backwards, there's a diode across the power connection that blows shorted, which usually protects the rest of the circuitry.
As long as it's just the diode it's a relatively minor repair, but there is the possibility that something else is damaged, such as the audio chip or the RF final.
As long as it's just the diode it's a relatively minor repair, but there is the possibility that something else is damaged, such as the audio chip or the RF final.
Maxtrac 300 D34 Power Problem
Does it mater whether the on/off switch is on? If it doesn't, try checking the polarity protection diode. Turn switch off, connect an ohmmeter to the power connector, note reading, then reverse the ohmmeter leads and note that reading. Use the "diode" setting on your ohmmeter if it has it. The ohmmeter should show open in one direction, and nearly a short in the other direction If it shows a short in both directions, it could be a bad polarity protection diode (fairly inexppensive) or a bad output transistor or module (more expensive). In either case, you'll probably have to take it to the shop, but this should give you some idea of what to expect.