DIY 500 EQ not working

[cRiTza]

Hello i built a couple of Atlantic Phonic Shaper BAX eq a while back and then sold them.
I got them returned later because one unit was faulty.
The high frequency knob only has boost, and needs to be wound all the way down to be at unity.

Anyone experienced who could tell me whats wrong

Its the top one that is bad.

Thanks in advance
/Christer

 

[mjrippe]

First clean the solder side of the PCB with isopropyl alcohol and a toothbrush to get all of the flux and solder spatter off.  Then look at the solder joints with a magnifying glass and see if there is a cracked joint on the pot.  In the photo the knobs look crooked, like they may have been smacked in shipping.  This could cause a cracked joint or even worse, a cracked wafer in the pot.

 

[cRiTza]

First clean the solder side of the PCB with isopropyl alcohol and a toothbrush to get all of the flux and solder spatter off.  Then look at the solder joints with a magnifying glass and see if there is a cracked joint on the pot.  In the photo the knobs look crooked, like they may have been smacked in shipping.  This could cause a cracked joint or even worse, a cracked wafer in the pot.

Thanks for helping out, dont have any Isoalcohol atm, have to get.
I cannot see any cracked pots.

 

[mjrippe]

Are those knobs bent/crooked or is it just the camera angle?

 

[cRiTza]

Are those knobs bent/crooked or is it just the camera angle?

The knobs look fine to me, its the weird angle. Could it be that the solder joints connect to each other because of too much solder?

 

[mjrippe]

The knobs look fine to me, its the weird angle. Could it be that the solder joints connect to each other because of too much solder?

Yes, a short is one possibility.

 

[cRiTza]

Yes, a short is one possibility.

Is it easy to determine with a multimeter? Or how does one go about in these situations?