Hartke ha5500 won't turn on?!!!!!!!Someone Please Help me!

[holloman3000]

I just played through my amp on this past Sunday. Then today while doing a sound check, it turned off....I mean completely shut down and WILL NOT TURN BACK ON!!!! Before all this happened, my amp had a bad hissing, popping, and static sound. The hissing noise increased as I turned the tube pre-amp level up. And when I started playing through the amp, everything seemed fine, but the longer I played the hotter the amp got....and sometimes it shuts down with the power light indicator remaining on, but still with NO SOUND. Then after waiting a few seconds, the sound came back in again. JUST NEED TO KNOW WHATS THE DEAL HERE WITH MY AMP. CAN IT BE FIXED, OR IS IT COMPLETELY GONE?

[Enzo]

Everything works until it doesn't...

Of course it can be fixed. Could be as simple as a bias adjustment, or it could have failing parts in a number of sections. ALl this will require at the very least taking volattge readings, and pretty surely soldering parts on the circuit board. if you are not at that skill level, then the amp needs to go to a tech.

[holloman3000]

I don't want to have to take it to a tech as I have no money for that right now. But I replaced the fuse and it turned on. But I accidentally replaced it with the wrong fuse(20A 250v) it stayed on but I heard some buzzing going on and immediately shut it off. And the power input terminal was blistering hot just in a few seconds. Just using the fuses I had on hand, which were 10A 250v, when the amp takes a 12A 250v , it instantly blew the 10A 250v, but tomorrow I'm going to shop around for the correct fuses. If the amp remained on with the wrong fuse and was hot, could the reason for it running hot be due to the incorrect fuse or something else? How do I perform a bias adjustment for this kind of amp?

[MikeH]

The fuse is not the problem. FYI (for future reference) replacing a fuse with a higher amp rating is REALLY bad. The fuse is there to protect the expensive components in your amp from frying. Shorting out a fuse or increasing it's value takes away that protection and will likely lead to more damage.

[MikeH]

Also, I believe this amp is a tube pre with a solid state output section? If that's the case this wouldn't likely be a bias issue, unless some sort of failure (like a shorted out cathode resistor) caused the preamp triode stage to come "un-biased". This doesn't sound anything like that to me. Sounds like a power issue.

[wagdog]

Turn the amp off, unplug it and take it to a tech. Please.

[Enzo]

Mike, solid state amps have bias too. One sets idle current in a solid state power amp, it just is a totally different kind of circuit. And one sign of an underbiased power amp is that it runs REAL hot.

[olddawg]

My guess is that you have a shorted output device. Output IC or transistors depending on what it has. Then you over fused it and caused a lot more damage. Take it to a tech. Don't power it on again. We see this all of the time with SS amps. People keep sticking fuses in them and turn them on. Each time they cause more damage. That 20 amp fuse was like wrapping tin foil around a smaller fuse. I've seen people even cut fuse length pieces of aluminum dowel for a blown fuse. Stop. The more you do, the more extensive ( and expensive) the repair will be. And btw, fuses are there to keep you from burning your house down, not really to protect circuitry.