Daughter Board on 2250

Post by **mhyde71** » Sat Oct 18, 2008 6:13 pm

Could someone that has a 2250 (maybe YOU STROKD perhaps) anyone really, please take a couple macro close up pictures of the daughter board for the fan????

I am unable to get any more than 5.75-6.25 DCV out of my fan plug off the daugther board... wanna see if I can see some inconsistancies, compromised componants, etc... so I know how to attack, or maybe if someone already knows/has ideas that would be great just the same!?!?!??? P

Pls thx
matt

Post by **Jacampb2** » Sun Oct 19, 2008 7:18 am

On the ZX amps, there is a big current limiting resistor before the fan, it drops voltage at the fan to ~6V, in the event of a thermal or overload condition, a small transistor switches on and feeds the full 12V to the fan bypassing the resistor. This is what gives it it's two speeds, a low idle speed, and high speed if there is a fault. It could be the 2250 is set up the same way, although this is just a stab in the dark

Later,
Jason

Post by **mhyde71** » Sun Oct 19, 2008 7:26 am

Jacampb2 wrote:On the ZX amps, there is a big current limiting resistor before the fan, it drops voltage at the fan to ~6V, in the event of a thermal or overload condition, a small transistor switches on and feeds the full 12V to the fan bypassing the resistor. This is what gives it it's two speeds, a low idle speed, and high speed if there is a fault. It could be the 2250 is set up the same way, although this is just a stab in the dark

Later,
Jason

kinda thought same thing, But after telling Phil (Koehn), about the fan output being 6dcv only... he didnt make any mention about it being designed that way... instead he offered that one of the tech's there had asked I do thbe following:

1. Measure voltage on fan connector with fan connected
2. Measure voltage on fan connector with fan disconnected
3. Measure voltage on brown connector (main board to sub board 2 pin connector on the middle of the sub board)
4. Do fans spin or not?
5. Measure voltage across big 2 Watt resistor with fan connected and disconnected.

I am unable to (or have chosen not) get inside the amp to that degree as it is currently pegged upside down and is a bitch to get out (great for theives, bad for me

)... so i can and only have done what I can do from the outside... which is the first two... I may have to put in the 2125 for downtime with the 2250.. as i have new sink on the way anyways maybe it'll make sense to do so when that arrives...

but, if it was simliar to ZX config's... what do i have to do to get it to 12V?? I tried letting it "Breath" real big last night to get warmed up, but nothing...

Post by **Jacampb2** » Sun Oct 19, 2008 11:09 am

Well, with the fan out of circuit in a ZX, you have 12v across the terminals. The voltage only drops when there is a load present. That is probably why they told you to check with the fan out of circuit. If it only has 6V with the fan out of circuit, then something is definitely messed up.

What exactly is the problem you have? Does the fan not run at all? Some fans don't like being in the 6V range. I have seen a few ZX amps that the fan got old and sticky enough that it would not turn at all at 6V, but ran fine at 12V.

The thing is, if it is set up like the ZX, then the fan will not run at high speed unless the amp faults. If the amp thermals or O/L's, then the protection circuitry turns the fan on high, and mutes the amp until the fault clears or power is reset. The reason to run the fan at low speed all of the time is to minimize fan noise. There was some trouble w/ insufficient air flow, and that is why the V2s went to a true variable speed fan, and a higher flow fan.

Good Luck!
Jason

Post by **mhyde71** » Sun Oct 19, 2008 11:36 am

Deal is:
first, well, it isnt a PG fan or anything it is a 12v Stinger crossflow fan... When I first got the fan I took the two leads and touched them to the pins sticking out the side of the 2250 and spiiinnnn! - worked! great! Thinking/knowing that I would be completing the install soon, I simply wired the fan, temporarily, directly off the remote/ground from the amp.. becasue I didnt have the two pin plug that goes in there to the 2250 fan port. So i ordered one from PG... when it came in, I wired it up.. but something has gone amiss.. A spark took place and now it only puts out 6dcv... and fan doesnt work period... Like I said I tried to let the amp get nice and warm last nightbut nothing.. but didnt get it all that warm so not sure if that's the deal.. I think that Spark might not have been good.

STROKD · Post by **STROKD** » Mon Oct 20, 2008 11:42 am

As I said, I don't have a macro lens, so this is the closest I could get. It took me 5-10 minutes to ge tthe lighting and flash set perfect for these. Hope they help you out Matt!!!

Post by **mhyde71** » Mon Oct 20, 2008 2:33 pm

looks good, very good... cant wait until I get home to look at it more closely.. but if i remember correctly, it appears that maybe on mine there is a lil darkening around the resistors?? maybe, not sure but seem to recall that... - edit- shit I wont be able to look at it whence I get home, it'll be dark - damn... have to wait until tomorrow moring... I might have to throw in the 2125 and pull out the 2250 to allow me to get inside the amp...

Thanks-Much, once Again, strokd!
matt

STROKD · Post by **STROKD** » Mon Oct 20, 2008 2:53 pm

mhyde71 wrote:looks good, very good... cant wait until I get home to look at it more closely.. but if i remember correctly, it appears that maybe on mine there is a lil darkening around the resistors?? maybe, not sure but seem to recall that... - edit- shit I wont be able to look at it whence I get home, it'll be dark - damn... have to wait until tomorrow moring... I might have to throw in the 2125 and pull out the 2250 to allow me to get inside the amp...

Thanks-Much, once Again, strokd!
matt

Sure and good luck with it! I'd taken a pic of the black amp, but didn't feel like taking the plexi off of it, that is pics of the shrouded amp through the plexi. I couldn't get the whole board in focus up that close so I had to take two focuses on different points. Hopefully you can make out all the colors of the resistors.

Post by **mhyde71** » Mon Oct 20, 2008 3:24 pm

STROKD wrote:
mhyde71 wrote:looks good, very good... cant wait until I get home to look at it more closely.. but if i remember correctly, it appears that maybe on mine there is a lil darkening around the resistors?? maybe, not sure but seem to recall that... - edit- shit I wont be able to look at it whence I get home, it'll be dark - damn... have to wait until tomorrow moring... I might have to throw in the 2125 and pull out the 2250 to allow me to get inside the amp...

Thanks-Much, once Again, strokd!
matt
Sure and good luck with it! I'd taken a pic of the black amp, but didn't feel like taking the plexi off of it, that is pics of the shrouded amp through the plexi. I couldn't get the whole board in focus up that close so I had to take two focuses on different points. Hopefully you can make out all the colors of the resistors.

I can, looks good... let me know once you power it up and are able to put dmm to it.. like i said the 2125 puts out 12v, so i dont see why the 2250 wouldnt either unless that's what the daughter board is all about, and purpose it serves...

Thanks again mang! I appreciate it

Daughter Board on 2250

Daughter Board on 2250

Hope this works...