Philips Wake-Up HF3520 Power supply repair

Written By: Thomas Widmaier
  • Comments: 36
Philips Wake-Up HF3520 Power supply repair

Difficulty

Difficult

Steps

1

Time Required

1 week

Introduction

The IC (chip) inside the lamp seems to die slowly resulting in flickering/flashing lamp operation when using the radio. Also, the buttons may become unresponsive.

The problem occurs specifically when the device is cold and/or humid. Heating up the IC makes it work again.

  1. XcDOIWyOmmJinSrV

    • On the main PCB with the power jack, replace the MXT2410 switchmode regulator IC (SO-8 Package).

    • Currently a seller "adeleparts2010" has this chip available (might change in future).

    • The ACT4060 is pin-compatible but can be a problematic choice. It can blow up and damage LEDs, so don't use it.

    Bonjour,

    Où trouver ce MXT2410 (CMS 8 pattes)?

    Thieb -

    Bonjour, je l'ai acheté pour 2€ ici : https://fr.aliexpress.com/item/100500563...

    Broffrey -

    I always bought from this seller:

    https://www.ebay.de/str/adeleparts2010
    Very good and fast.

    Thomas Widmaier -

    Thanks a lot, I was able to fix my HF3520. CHEERS !

    Broffrey -

    Hallo warum sind R3, R4, und R5 markiert? Ausgetauscht werden soll doch der MXT2410 daneben oder?

    Über eine Antwort würde ich mich freuen.

    Nadine -

    Sehe ich auch so.

    VauWeh -

    Note to the marked resistors:

    I initially could not find MXT chip, and thought I was smart and replace with an ACT4060 from Corvo, but that was not stable and blew up on me. For that wrong fix, I had to modify the feedback resistor divider. That is NOT necessary when just replacing MXT2410.

    Sorry !

    Thomas Widmaier -

Conclusion

Arbeite die Schritte in umgekehrter Reihenfolge ab, um dein Gerät wieder zusammenzubauen.

Author

Thomas Widmaier

Member since: 05/03/13

2063 Reputation

29 comments

Hi Thomas,

I have the same problem, but i do not understand what you are doing with the R3 and R4. If i remove R4, with what should i replace it?

Or how should i measure it?

Thanks in advance,

Arnoud

Arnoud Otten -

Can somebody do this for mine?

June Goto -

Can some one do this for me??

June Goto -

I can only do it in Germany

Thomas Widmaier -

Hallo Thomas,

ich finde das ist eine tolle Anleitung zur Reparatur des Lichtweckers. Ich hatte mich auch auf den Austausch des MXT2410 konzentriet. Es kam dann aber doch anders. Nach ca. 2-3 Wochen warten auf den ACT4060 war dieser schnell eingebaut. Das Ergebnis war enttäuschend. Keine Änderung, die 5V waren nicht messbar. Bei der weiteren Fehlersuche stellte ich fest, dass der ACT4060 und die zugehörige Drossel schnell warm wurden. Jetzt ging es an die Suche nach einem Kurzschlußkandidaten. Er war dann schnell gefunden: D3 (SK24). Eine andere Schottkydiode eingebaut (diesmal aus der Bastelkiste) und es wurde wieder Licht und Musik.

Freundliche Grüße,

Roland

rpg -

Thanks for the feedback. I wasn´t 100% sure the ACT4060 can work correctly. Your feedback has confirmed it will work.

Did you make a modification to the resistors ? Did you measure the voltage ?

Thomas Widmaier -

Hallo Roland,

vielen Dank für den Tipp mit der Schottky-Diode!

Bei mir war es nur diese Diode, die defekt war.

Nach dem Tausch läuft der Wecker wieder!

Viele Grüße

Andreas

hebel23 -

I was able to use this guide to bring a Philips Wake-Up HF3520 back from the dead. Was able to source a MXT2410SX IC via ebay (5 for $10.23), so just swapped the IC and did not touch the resistors. Thank you OP for identifying the failing component.

John Morris -

I haven’t attempted the repair yet, but the tip about humidity/cold was genius!! My lamp magically works again every time I shut the windows and put the heat on… I never would have figured this out without this clue. For me this isolates the problem to the chip. Thank you!!

marziplan -

Hallo Thomas,

mein HF3520 spinnt auch, wenn es kalt ist. Ich habe selber keine Ahnung von Elektrotechnik. Hättest du Interesse und Zeit ihn zu reperarieren. Ich wohne in München Oberföhring.

Viele Grüße

Mathias

mathiaskloss -

Hier gibts keine Privatnachricht, leider. Bitte eMail an ifixit@e-mail.de

Thomas Widmaier -

Sicher kann ich es probieren, allerdings hab ich nur den Alternativchip hier noch irgendwo, der MXT müßte erst bestellt werden.

Alles ohne Garantie ;-)

Kannst es schicken oder vorbeibringen. Westendstraße nähe OBI. Genaueres müßte ich eine PM schreiben.

Thomas Widmaier -

Hallo Thomas,

ja die Widerstände mussten etwas angepasst werden. Auf der Platine ist Platz für einen kleinen SMD-Trimmer.

Das machte die Sache etwas einfacher. Mit Hilfe des Datenblattes und Kontrollmesungen der Spannung war die Einstellung kein Problem.

Nochmals Danke für deine tolle Anleitung,

Viele Grüße Roland

rpg -

Worked for the second time with the ACT4060 and adapted resistors. However, this IC is actually specified only up to 20V, I saw afterwards. That could explain your blow-up, Thomas.

Once the external 24V power supply was also broken. I replaced it with a 12V power supply I had left over from an external hard drive.Seems to work fine and also protects the ACT4060 :-)

baatzi -

Worked for the second time with the ACT4060 and adapted resistors. However, this IC is actually specified only up to 20V, I saw afterwards. That could explain your blow-up, Thomas.

Once the external 24V power supply was also broken. I replaced it with a 12V power supply I had left over from an external hard drive.Seems to work fine and also protects the ACT4060 :-)

Samson Ogboji -

The power source must be 17V - 24V. If power is lower than 17V the light on maximum is yellow instead white. What i do. I replaced IC1 with ACT4060, added 1K resistor for R3+R4, and added 12V DC-DC for ACT4060. Remove L5, get 24V from one pin to DCDC in and connect second pin L5 to DCDC 12V out. I think this construction must work longer. For DCDC i use MP1584 module that i found in my parts box, i think also LM7812, LM7809 is suitable

Mike Tornado -

And yes its still working without any problems

Mike Tornado -

Hi!

Last week our HF3520 exploded in the middle of the night. I opened it and I found in another internal part (not the one you arranged) the follow stain: Damage

I don't know if my problem is the same as yours.

@goaty do you remember if inside of your lamp had the same stain?

Thank you!

Óscar Lestón -

The strain in the middle besides the coil and the capacitor is just glue to keep the cable in place.

Look for other damage like blown up capacitor.

Thomas Widmaier -

Thank you so much Thomas @goaty for this detailed Fixit !

Eventhough i have experience in electronics i would never thought about the power IC for this behaviour.

II've replaced the IC with the MXT2410SX that you can find on ebay here : "https://www.ebay.com/itm/393179218389" the lamp and all it's fonctionnalities is perfect since then ! I did that like 6 months ago and it still working perfectly (sorry i've just had time to give my feedback).

Changing the IC is a little bit technic but it still conceivable with some tutos for non experienced persons.

I'm glad to discovre this community thanks to your fixit i'll try to add some of mines as possible.

Hassan Barutchi -

Vielen Dank für die gute Anleitung!

Wenn bei dem Wecker irgendwelche Tasten nur noch unzuverlässig reagieren, kann man die Gelegenheit nutzen, um die zu reinigen:

- mit einer spitzen Pinzette die das weiße Klebeband vorsichtig abziehen

- Klebeband mit der Pinzette festhalten und mit einer zweiten Pinzette das im Inneren vermutlich dunkel angelaufene Metallplättchen abziehen

- Metallplättchen vorsichtig wieder glänzend polieren (bei mir hat einer der spitzen blauen Poliergummischleifer von Proxxon perfekt dafür funktioniert)

- Plättchen und Kontakt mit Isopropanol reinigen

- Plättchen wieder in seine Aussparung kleben und Klebeband mit Plättchen zurück auf die Leiterplatte kleben, vorsichtig ringsum wieder gut andrücken.

Wozu das denn -

My HF3520 is down.

May I ask a question? I don't know much about converter, but why do you use an ACT 4060 ? The ACT4072 is 1.222V (but do we care?) and support 30V input.

Does it work better?

(by the way, anybody has the mxt2410 fact sheet?, and what does all this numbers mean?)

rat.aspert -

I thought I was smart by using ACT4060 as replacement of MXT, but it did not work, and blew up on me, so I wrote that it is not good replacement !

Better buy MXT2410 original from China, 10pcs for around 10Dollars, it works perfect.

Thomas Widmaier -

Thanks! It was the problem in my case as well. I did't want to use new MXT2410 because I suspect that it would die after few years again. Thus, instead of ordering new MXT2410 I just desoldered it, as well as removed the Shottky diode and the inductor, and installed a bypass from a readily available module based on MP1584 (just because I already had one at hand), for example: https://www.tinytronics.nl/shop/en/power...

Alexey -

Just changed the IC MXT2410 on my HF3510 and it works well now !

Thanks a lot

The symptoms was that the buttons do not work too but also the clock make noise in the middle of the night

Julien F -

On eBay there is a seller "adeleparts2010" which is very reliably sending replacement parts from China. No problems had whatsoever.

Thomas Widmaier -

Hatte ein ähnliches Fehlerbild. HF3520 schaltete sich nach einem Stromausfall nicht mehr ein. Habe daraufhin den unteren Schacht (siehe Schritt 2) entfernt und das Innere ca. 5 Sekunden mit dem Föhn erwärmt. Danach den Stromstecker wieder eingesteckt. Deckel anbringen. Läuft wieder. Keine Reparatur im engeren Sinn aber im Vergleich zur SMD-Löterei sehr minimalinvasiv.

Thomas Aigner -

I used this guide as a basis for opening up the unit. I wanted to fix the touch buttons not working any more.

After step 4, I noticed the buttons were working without the display panel, so I cleaned it and put it back on – and my buttons worked again.

Felix -

Hello! My HF3520 suddenly cut out in the middle of the alarm and now is non-responsive. When plugged in, there's no display or response to the buttons. I've left it unplugged for a while, and also plugged it in for a while but nothing happening. I can't believe that it's unfixable and I'd really like to fix it or take it to a repair cafe. Has anyone else had a similar issue? I'm trying to work out if it's most likely to be a chip / bulb/ cable issue. Does anyone know what bulb it takes?

Olivia Hanson -