Fisher 1225 Help

[sthalhelm]

hello I ask for help for a metal detector Fisher 1225 when I operate the pin point the metal detector detects the object, but after a little it loses sensitivity gradually until you feel the object just resting on the plate, Thanks for any help and I apologize for my English translated by Google

[sthalhelm]

[kt315]

vvv

[Koala]

hello I ask for help for a metal detector Fisher 1225 when I operate the pin point the metal detector detects the object, but after a little it loses sensitivity gradually until you feel the object just resting on the plate, Thanks for any help and I apologize for my English translated by Google

sounds like my 1265x which turned out to be a capacitor

https://www.geotech1.com/forums/showthread.php?24776-Small-problem-pinpoint-mode-1265x&highlight=1265x

[Altra]

From the schematic you posted, there is 1uf capacitor connected to the pinpoint switch and pin 5 of the op-amp. As Koala stated this could be a bad capacitor. It may also be dirt and oxidation on the circuit board. Which could cause the 1uf capacitor to lose it's charge through leakage currents. Try cleaning around that 1uf capacitor (top and bottom) of the pcb with alcohol with a toothbrush before changing the capacitor.

[sthalhelm]

Grazie prover? con la pulizia e alla fine con la sostituzione del condensatore

[kt315]

i know pizza, ciao, spagetti, bella donna, amur. thats all.

[sthalhelm]

thanks I will try 'with the condenser cleaning and possibly with the replacement

[sthalhelm]

To remember if you come to Italy "Bella Donna"

[kt315]

you have to learn ESR definition, than you will measure it by, then to buy ESRmeter or ESR kit meter. not so long way to fix 1225.

[kt315]

[ATTACH]45588[/ATTACH]

please send pics of your board in hight definition HD on good light on my email [email protected]

[kt315]

thank you very much for the pics you sent me but... please read my opus before to do

https://www.geotech1.com/forums/show...here-share-out

sorry that i must teach you by those ABCD like in 1st stage of beginner school.

[sthalhelm]

Hello everyone, I cleaned the circuit board but no result, so I replaced the 1?f capacitor but still no result the pinpoint does not improve. Sorry for my english translated by Google

[sthalhelm]

Capacitor 1 micro f Sorry

[kt315]

guys

i ask you to help sending me perfect pics. you send pics like a trash. I REALLY WANT TO HELP YOU BUT WHY YOU DO NOT WANT HELP YOURSELF.

A few days ago I have a rare oportunity to repair and seting this obsolete detector. In order to adjust it after changing a few IC's I used the same method as I do it before with 1266. Tips to adjust 1266 were posted here on Geotech and they were good so I decide to do it with 1235 too. I try and was supprised with result. It works perfect as with 1266. Here are my tips for adjusting 1235 X according to 1266.
Here is the setup procedure for the 1235-X:
-Front panel controls:
Turn SENS knob fully anticlockwise to insure good battery voltage. A loud audio signal indicates adequate batteries.
DISC power ON and at "0".
SENS knob turned fully clockwise.
FREQ knob could be set anywhere.
-Internal trimmers:
Set Ground ---- here deleted part bacause you are not wish be cooperative
Set Static
Set Disc
Set Threshold
Set Audio
No audio should be heard at this point.