Fuse for the Itermatic Malibu ML 100THB Model Power Pack?

There is not a fuse.
Following link has specific steps for troubleshooting, plus warranty information and installation tips for getting power pack to last longer:
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html#troubleshoot

Gene

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If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

There is not internal schematic of the Malibu ML900 series power pack... you could take one apart and post the information on your website.
If you want basic tips for installing ML900 series power pack, the following link has detailed information and tips to help do-it-yourself folks...
Correct installation will ensure power pack lasts longer:
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html#wire

Gene


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If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

1) Copy following link for ML series trippers, troubleshoot, 5-year warranty info, and tips to keep power pack running longer.
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html

2) Add comment if more help is needed. Jan 2013.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

http://waterheatertimer.org/Malibu-power-pack-stopped-working.html

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

http://waterheatertimer.org/Malibu-power-pack-stopped-working.html

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Hello Maggie.
Timer is not 100% identified
Intermatic analog ML series power packs and manuals appear on following link:
http://www.intermatic.com/products/professional%20lighting/low%20voltage%20landscape%20products/power%20packs.aspx
Malibu ML series manuals appear on following link, and are same as Intermatic:
http://www.malibulights.com/customer_service/owners_manuals.aspx

Open following link for general instructions written in troubleshoot format, plus tips for maintaining power pack and ordering additional trippers:
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html

Add a comment for more help, and include in-focus photo of timer posted on Flickr for possible information

Open following link for power pack resources including link to Intermatic ML series trippers.
Same tripper fits all ML series timers.
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html

For all Intermatic trippers and parts:
http://waterheatertimer.org/Intermatic-trippers-and-parts.html

Upvote the help.
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

There is no trip switch, or reset button for ML series Intermatic/Malibu power packs.
Your question shows LV and not ML, so there might be a different model number, but generally power packs are not a repairable item if power pack is broken.
Add a comment with in-focus photo of your timer for possible identification difference between ML series and your power pack.
http://www.fixya.com/support/r6568559-post_photograph_fixya_questions_answers

Open following link for Malibu troubleshooting steps and possible assistance:
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html
Note: Intermatic links sometimes don't work on weekends, April 2011.

Power pack parts are not available except for trippers
http://waterheatertimer.org/Intermatic-trippers-and-parts.html

You posted under Intermatic/Malibu ML series power pack.
There are no replacement clock mechanisms or timer modules for ML series power packs.
If you found a replacement clock motor source, add a comment add a comment here so others can benefit. If you find a way to repair clock motor, also add a comment.
Many people have same problem and will benefit from your discovery.
To work around problem, buy cheap plug-in timer, set power pack to override, and then plug power pack into cheap timer.
ML series has 5 year limited warranty.

Open following links for troubleshooting resources, warranty links, manual links and Intermatic parts:
http://waterheatertimer.org/Malibu-power-pack-stopped-working.html
http://waterheatertimer.org/Intermatic-trippers-and-parts.html

Sounds like you have a power supply problem in the amp. I am assuming the fuse you are replacing is intergraterd into the AC connection. You need to dig deeper. If you are not an electronics person you will need a tech.