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HP 5316a Repair

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5316AOnce again, knowing no end to repairing things, I saw an HP 5316a come up on eBay for cheap ($20), that I bid on first thing, and ended up winning. Not sure I WANTED to win it, but hey, it’s a repair, I’m cool with doing those. Maybe I’ll be able to resell it, maybe not. *shrug*

3 days later, it showed up on my doorstep via FedEx, and looked to be in good condition, except the missing handle and feet, as described by the seller. Initial power up showed it power up okay, but never register any count. The gate LED would trigger, as would the sensitivity LED, and both could be adjusted. I did get a alternating flashing of the HP-IB LEDs on the front panel though (at this time, I didn’t know what this meant).

After opening the unit, I noticed two empty sockets, one on the HP-IB (GPIB) card, and one on the main board. It appeared they were used for a ribbon cable between the two, but the cable was missing. Also, another power up showed an E2 error (which translates into a failed HP-IB card)… which isn’t surprising given the connection to the HP-IB card was missing. I’m just not sure why it booted okay previous to that.

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Ampeg B-80N Repair

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Ampeg_Jet-70My dad recently dropped off his guitar amp, an Ampeg B-80N from the late 70’s or early 80’s, for repair saying that it wasn’t working. It was behaving oddly, then just stopped working one day. Figuring it should be easy to fix, I gladly said I would take a look. First thing was obviously pulling it apart and seeing if anything obvious was wrong. The trick to taking these apart is to remove the speaker grill, then the 9 screws that hold the speaker on, drop it down and unplug the spade connectors on the driver. Then unscrew the amp on the back, and pull it straight off, and then pull the speaker wire out of the hole that it threads through down to the sound box. Make sure to note which lug plugs into which spade on the speaker, btw. I just snapped a quick picture with my phone.

Anyway, pulling the amp, there was nothing obvious wrong other than being a rather old design of a, I believe, class AB amp. It uses a diode pair (STV4H) to bias the output transistors, and unfortunately, that diode pair is at this point, unobtanium unless you want to spend $60 on ebay.

Okay, anywho, after the initial look, I contacted Ampeg (or rather, loudtechinc) to get the schematics, and manual for the amp. Sadly, they don’t post schematics on their site like Fender, but if you contact them, you can ask, and they’ll send you back an indemnity clause that you agree to not electrocute yourself, then they’ll send you the info. Took about 2 business days to get the schematics ((btw, I find these old schematics funny given they use the old symbol for polarized capacitors)).

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Apache AL13P Repair

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Apache AL13P Broken Trace FixI just received an Apache AL13P laminator I purchased off eBay (for doing toner transfer PCBs), as not working, for $15 with $15 shipping (so, $30 vs a new one for $90 from Amazon). Listing said the motor worked, but the controls didn’t. Figured it would be something easy.

Item arrived from FedEx saying they had inspected it (guessing they wondered about the odd weight of the box), but otherwise in very good shape. Looking at the unit, it had obviously been dropped in shipping to the original purchaser, as one of the top case tabs had broken, and upon opening, the transformer had broken loose of the power PCB (breaking a trace at the time, as well as breaking a leg/lead off the primary side of the transformer). So, repairing we will go!

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