Ampeg Portaflex: Reliability and Repair

[revolver]

Five or six years ago I bought an ex-demo Ampeg PF-350, as well as a PF-210HE cab.  Soon after, the band I was playing bass with went on extended hiatus, so other than a quick check at the time of purchase, the amp didn't get any use.  Inevitably (and probably unsurprisingly), now that I finally need to use it again I'm consistently getting a fault light / shutdown after a few minutes of use (regardless of gain / volume).   I realise that this was a common problem with the earlier model Portaflex heads, so was just looking for any advice on the following:

 

• Are these heads generally worth repairing in terms of cost and longer-term reliability?  (I appreciate that's a broad question without knowing the specific cause of the fault, but just looking for experience / a general rule of thumb).

 

• Assuming it's worth looking into a repair, would people recommend an official Ampeg service centre, or an independent specialist?  Coincidentally, one of the three official UK service centres is local to me (Sontec in Norwich), but they appear to cover Yamaha musical instruments generally, as well as TV and home entertainment brands, plus their Yell / Google ratings look pretty poor, at least for customer service.

 

• Assuming a repair isn't viable, what's the view on the reliability of Portaflex heads being built today?  For example, if I were to buy a new PF-500 from a dealer that offers three or more years of warranty,  could I be reasonably confident that it should be as reliable as any other brand of Class D amp, or would I have to be constantly concerned that it might decide to shut itself down mid-gig?

 

Thanks!

Edited May 18, 2023 by revolver

[BassmanPaul]

Maybe the amp doesn't like your playing!

 

I hope you can get your problem sorted. 

[Riverbassman65]

You have the old chipset in it. If you take it to a certified Ampeg repair shop they can get that fixed for you.  I have a PF800 and have only had it shut down twice in the 4 years I’ve owned it, because of excessive heat(stage temp in excess of 50c). 
I now use mine for smaller gigs with a PF 115LF.  For bigger shows I use an SVT7 Pro with 2 PF115LF cabs.

[msb]

Just insure that a qualified repair person is doing the work. There are a surprising number of hacks around.

[BassAdder60]

And or … buy an amp head that doesn’t have a history or thermal shutdowns !